Step one: Never use that setup where you have it. Open blasting, if you must, should be done outdoors with a lot of thought being given to avoiding potential ignition risks.
Looks like you intend to blast it into a jacketed base? Purging will be safe like that, outdoors, but remember to keep the water heater and pump far away from the base, best if separated by a wall, again with careful thought given to which way the wind is going to carry your evaporating butane vapor.
Step Two: Your solvent needs to be as cold as possible, cooling cans that far can be risky so it’s best to have a small sealed pressure vessel you can bury in dry ice, vacuum the atmosphere out with your pump, and then add the amount of solvent you want to run to that tank first. You’ll want at minimum 5lbs of solvent for every lb of material, but a lot of us prefer about 8:1 when running nice and cold.
Step Three: Upgrade to this. Figure out how to repurpose your existing hardware as a filtration column, get your hands on a few lids, reducers, fittings, hoses, pipe mounts and unistrut and mount the columns of the new system to a temporary structure to make it less top heavy. You can build yourself a nice tee stand out of 2x4s that still allows your collection to sit on the ground while supporting your columns.